Planetary wave coupling in the middle atmosphere (20-90km): A CUJO study involving TOMS, MetO and MF radar data

Abstract

Abstract. The atmospheric coupling due to Planetary Waves (PW) in the middle atmosphere (20-90km) has been studied using TOMS, MetO and MFR data. The wavelet and wave number analyses have been applied to all parameters at five CUJO (Canada US Japan Opportunity) locations. The CUJO network covers latitudes of 31-52° N and longitudes from 81° W to 142° E, and allows for the assessment of longitudinal variability. The results of temporal and spectral comparisons show that the total ozone (TOMS) and MetO temperatures at low stratospheric heights (typically 100mbar) have high values of correlation as well as similar spectral content. The eastward motions dominate at low stratospheric heights (100mbar), while westward motions became comparable or even stronger in the upper stratosphere (0.46mbar). During the summer months a reduction of PW activity has been observed in the stratosphere, especially at its upper heights, and in the upper middle atmosphere. The MetO (0.32mbar, 55km) and MFR winds (circa 60km) are in good general agreement, especially for the zonal component. Several examples of planetary wave activity at different atmospheric levels throughout the middle atmosphere have been presented. These examples include an eastward propagating 15-day disturbance with wave number 6, that has been observed only at low stratospheric heights; long-period (20-30 days) oscillations with wave number ~1 that have been detected in a wide height range (20-90km); and an oscillation with period near 16 days that was found only at mesospheric heights.

Planetary wave activity in the polar lower stratosphere

“…Large eastward wave activity in the Arctic with various periods preconditions the stratospheric circulation prior to the 2006-2007 and 2007-2008 SSWs, as expected climatologically (Labitzke, 1981;Limpasuvan et al, 2004) and observed during the recent Northern Hemisphere winters of (Pancheva et al, 2008b-2006(Hoffmann et al, 2007. Eastward wave amplitudes dropped sharply immediately prior to the onset of the major SSW in late February 2008 (Fig.…”

“…Planetary wave amplitudes are larger in the Northern Hemisphere than in the Southern Hemisphere due to larger thermal and Correspondence to: S. P. Alexander (simon.alexander@aad.gov.au) orographic forcing (Andrews et al, 1987). Stratospheric waves generally propagate eastward relative to the ground in the Southern Hemisphere (Hartmann, 1976;Shiotani et al, 1990), while quasi-stationary waves dominate the Northern Hemisphere (Chshyolkova et al, 2005).…”

“…An increase in planetary wave activity is noticed prior to the onset of an SSW which preconditions the atmosphere (e.g. Chshyolkova et al, 2006;Hoffmann et al, 2007), leading to an upward and poleward motion of heat flux (Andrews et al, 1987). A downward circulation causing adiabatic heating in the stratosphere results from the deceleration of the eastward flow by planetary waves (Liu and Roble, 2002).…”

Arctic tidal characteristics at Eureka (80° N, 86° W) and Svalbard (78° N, 16° E) for 2006/07: seasonal and longitudinal variations, migrating and non-migrating tides

“…It becomes progressively weaker at the 78-80 • N locations. The differences between spectral features at Svalbard and Eureka, in time of occurrence and frequency, are typical of those already observed at middle latitudes Chshyolkova et al, 2005).…”

Winds and tides in the mid-latitude Southern Hemisphere upper mesosphere recorded with the Falkland Islands SuperDARN radar

“…Luo et al, 2001Luo et al, , 2002Manson et al, 2004Manson et al, , 2005Igarashi et al, 2002;Jacobi et al, 2007Jacobi et al, , 2009Middleton et al, 2002;Mitchell et al, 1999;Pancheva, 2000;Lysenko et al, 1994;Merzlyakov et al, 2001;Chshyolkova et al, 2005). In contrast, relatively little ground-based data has been reported from equivalent latitudes in the Southern Hemisphere (Brown et al, 1995;Fritts et al, 2010) with the majority of Southern Hemisphere observations coming from lower latitude tropical and extratropical sites (e.g.…”